JPH0447430Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The invention is used for automotive cooling cycles,
This invention relates to an improvement of a variable capacity swash plate type compressor capable of changing the internal volume of a compression chamber.

(Prior Art) As shown in FIG. 6, a cooling cycle 1 used in a general automobile air conditioner is driven by an engine (not shown) via a belt, a pulley 2, and a magnetic clutch 2a. a compressor 3; a condenser 4 that exchanges heat with external air to convert the gaseous refrigerant that has been adiabatically compressed into a high temperature and high pressure state into a low temperature and high pressure liquid refrigerant;
A liquid tank 5 temporarily stores this liquid refrigerant and removes moisture and dust in the refrigerant, and an expansion valve 6 that squeezes and expands this liquid refrigerant to form a low-pressure mist refrigerant.
It has an evaporator 7 that vaporizes this low-pressure mist refrigerant and cools the air blown into the vehicle interior.

As the compressor 3 used in such a cooling cycle 1, a variable capacity swash plate type compressor having a structure shown in Japanese Patent Application Laid-open No. 158382/1982 has recently been proposed. In this variable capacity swash plate type compressor, the reciprocating stroke of the piston in the cylinder is changed in accordance with the suction pressure of the compressor, thereby changing the discharge amount of the compressor, so that the suction pressure of the compressor remains constant.

When the suction pressure of the compressor 3 shown in FIG. 6 becomes constant, the refrigerant pressure at the outlet of the evaporator 7 (that is, the evaporation pressure of the refrigerant in the evaporator 7) becomes constant to some extent. Therefore, when the heat load becomes small, for example when the outside air temperature is low and you want to dehumidify with the evaporator 7, the expansion valve 6 that tries to keep the amount of superheat at the outlet of the evaporator 7 constant This is convenient because it is possible to avoid the so-called freezing of the evaporator under low load, which occurs when the refrigerant is throttled too much to improve performance, lowering the evaporation pressure of the refrigerant in the evaporator 7, and causing the condensed water in the evaporator 7 to freeze. Furthermore, since the discharge capacity of the compressor is changed according to the heat load, it also contributes to energy saving.

(Problem to be solved by the invention) However, such a variable capacity swash plate type compressor requires many movable or sliding parts, and it is important to keep these parts well lubricated. However, it was necessary to always store a suitable amount of oil inside the crank chamber, where the moving and sliding parts were installed.

However, the oil stored in the crank chamber leaks from the compression chamber into the cooling cycle through the sliding surface between the piston and cylinder, reducing the amount of oil stored in the crank chamber, and eventually causing damage to moving parts or sliding parts. There was a risk that the durability of moving parts would be impaired.

The present invention was developed to eliminate these inconveniences, and it reduces the amount of oil leaking from the crank chamber into the cooling cycle, keeps an appropriate amount of oil in the crank chamber at all times, and prevents moving parts or sliding parts from moving. The purpose is to improve the durability of the contact parts.

[Structure of the invention] (Means for solving the problem) In order to achieve the above object, the present invention provides a drive swash plate that is connected to a drive swash plate whose inclination angle is variable with respect to the drive shaft in the crank chamber. A rotating wobble plate is slidably connected, and a piston is connected to the wobble plate through a plurality of rods. a variable capacity slant housed in the crank chamber so as to be reciprocally movable, and changing the inclination angle of the wobble plate and the drive swash plate with respect to the drive shaft by changing the pressure in the crank chamber, thereby changing the reciprocating stroke of the piston; In the plate compressor, the suction port and the discharge port are communicated with the crank chamber through first and second control valves to control the pressure inside the crank chamber, and an oil reservoir is formed below the discharge port;
It is characterized in that the discharge port and the second control valve are connected to each other by a conduit having an opening near the bottom of the oil reservoir.

(Function) In the variable capacity swash plate type compressor of the present invention that employs such means, it is assumed that the oil stored in the crank chamber leaks to the discharge port through the sliding surface between the piston and the cylinder. Also, this oil is stored in an oil reservoir formed at the bottom of the discharge port. The oil stored in this oil reservoir is
When the opening of the pipe leading to the second control valve is closed, the pressure in the discharge port causes the oil stored in the oil reservoir to flow to the second control valve.
It flows out towards the control valve and is returned through there into the crank chamber. Therefore, it is possible to prevent the amount of oil stored in the crank chamber from decreasing as much as possible.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a schematic sectional view showing the piston discharge process in a variable capacity swash plate compressor according to an embodiment of the present invention, FIG. 2 is a schematic sectional view showing the piston suction process in the compressor according to the same embodiment, and FIG. The figure is a schematic cross-sectional view when the crank chamber pressure changes in the compressor according to the same example,
4 is a cross-sectional view taken along the line - shown in FIG. 1, and FIG. 5 is a cross-sectional view taken along the line - shown in FIG. 4.

As shown in FIGS. 1 to 3, the variable capacity swash plate type compressor 3 according to this embodiment is used in an automobile cooling cycle, and is rotationally driven by an engine via a belt, a pulley 2, and a magnetic clutch 2a. It has a drive shaft 11. A drive rod 11 a is fixed to the drive shaft 11 in a direction perpendicular to the shaft 11 and rotates together with the drive shaft 11 within the crank chamber 12 . This drive rod 11a
The drive swash plate 13 is connected at an angle to the drive shaft 11 using the pin 11b as a fulcrum, and the rotational force of the drive shaft 11 is transmitted to the drive swash plate 13 via the pin 11b. This drive swash plate 13 includes
A non-rotating wobble plate 16 is slidably connected via a thrust bearing 14 and a radial bearing portion 15. The radial bearing part 15 is a wobble plate 16
The thrust washer 20 and the snap spring 21 restrict movement in the thrust direction.

The wobble plate 16 is connected to a shoe 19 that is slidably connected to a guide pin 18 fixed to a casing 17, and the shoe 19 prevents rotation and guides movement in the direction of the drive shaft 11. It is becoming more and more common. This wobble board 1
Pistons 23 are connected to the pistons 6 via a plurality of rods 22 at substantially equal intervals in the circumferential direction, and the rotation of the drive swash plate with the rotation of the drive shaft 11 causes the wobble plate 16, which does not rotate, to move to the first, As shown in FIG. 2, it swings and the piston 23 reciprocates.

The connection between the wobble plate 16 and the rod 22 and the connection between the piston 23 and the rod 22 are made by ball bearings 22a and 22b as sliding parts, respectively, and the inclination angle of the rod 22 with respect to the wobble plate 16 and the piston 23 is variable. It's summery.

Piston 23 is mounted within a cylinder 25 formed in cylinder block 24. Inside the cylinder 25, a compression chamber 26 is provided in the front of the piston 20.
The rear surface of the piston 20 communicates with the crank chamber 12.

A suction port 27 and a discharge port 28 are formed in the compression chamber 26 . This suction port 27 is connected to the suction port 2 to which the refrigerant from the evaporator 7 shown in FIG.
9 through an inlet valve 27a. This suction port 29 is connected to the head 3 as shown in FIG.
It is formed in a circumferential shape inside 0 and communicates with a suction side pressure chamber 32 via a communication passage 31. Further, the discharge port 28 communicates via a discharge valve 34 with a discharge port 33 which communicates with a pipe for feeding refrigerant into the condenser 4 shown in FIG. This discharge port 3
3 is a discharge side pressure chamber 35 via a pipe line 50 which will be described later.
is connected to.

In the suction side pressure chamber 32, a first control valve 36 is held by a bellows part 37, and the bellows part moves up and down according to the pressure inside the suction side pressure chamber 32 to control the opening degree of the suction side communication port 41. It's starting to adjust.
Further, a second control valve 39 is connected to the first control valve 36 via a rod 38, and the two control valves operate in conjunction with each other. This second control valve 39
is provided in the discharge side pressure chamber 35 and is adapted to adjust the opening degree of the discharge side communication port 40.

These first and second control valves 36 and 39 are controlled by a bellows portion 37 that moves up and down according to the pressure inside the suction side pressure chamber 32, and when the pressure inside the suction side pressure chamber 32 becomes high, the suction side communication port 41 The opening degree of the discharge side communication port 40 is increased, and as the opening degree becomes lower, the opening degree of the discharge side communication port 40 is increased. Therefore, when the heat load in the cooling cycle is small, the pressure in the suction side pressure chamber 32 becomes low, the bellows part 37 extends upward, the opening degree of the discharge side communication port 40 is increased, and the crank chamber 12 to increase its internal pressure. Therefore, the pressure difference between the front and rear of the piston 23 during the suction process (see FIG. 2) increases, and as shown in FIG. acts. Therefore, the reciprocating stroke of the piston 23 is shortened, the internal volume of the compression chamber 26 is substantially reduced, and the flow rate of refrigerant circulating within the cooling cycle is therefore reduced, resulting in an appropriate adjustment in response to the low heat load. As the refrigerant flow rate increases, the suction pressure of the compressor gradually increases, and as a result, the suction pressure is kept constant.

Further, when the heat load in the cooling cycle is large, the pressure in the suction side pressure chamber 32 increases,
The bellows part 37 moves downward, and the suction side communication port 41
Since the opening degree of the crank chamber 12 is increased and suction pressure is introduced into the crank chamber 12, its internal pressure becomes approximately equal to the suction pressure. For this reason, the pressure difference before and after the piston 23 during the suction process (see Figure 2) is almost eliminated.
As shown in FIGS. 1 and 2, the wobble plate 16 and the drive swash plate 13 can be tilted to the maximum with respect to the drive shaft 11, and the reciprocating stroke of the piston 23 is maximized. Therefore, the internal volume of the compression chamber 26 increases substantially, and the flow rate of refrigerant circulating within the cooling cycle increases, resulting in an appropriate flow rate of refrigerant corresponding to the high heat load, so that the suction pressure of the compressor increases. The suction pressure gradually decreases, resulting in a constant suction pressure.

In particular, in this embodiment, as shown in FIGS. 1, 4, and 5, an oil reservoir 51 is formed at the bottom of the discharge port 33, and an oil separator 52 is installed to divide the discharge port 33 into two chambers. be. The oil separator 52 is made of a synthetic resin or metal net, and is configured to capture oil contained in the refrigerant flowing out from the discharge port 28 and allow the oil to fall into the oil reservoir 51.

This discharge port 33 and the discharge side pressure chamber 35 in which the second control valve 39 is accommodated are communicated through a conduit 50 having an opening 53 near the bottom of the oil reservoir 51.

In such a compressor 3, the oil stored in the crank chamber 12 is removed from the piston 23.
and the discharge port 3 through the sliding contact surface with the cylinder 24.
Even if the oil leaks up to 3, this oil is stored in the oil reservoir 51 formed at the bottom of the discharge port.
The oil stored in this oil reservoir 51 is transferred to the second control valve 3
When the opening 53 of the pipe line 50 leading to the pipe 9 is closed, the oil stored in the oil reservoir 51 due to the pressure inside the discharge port 33 is transferred to the discharge side pressure chamber 3 equipped with the second control valve 39.
It flows out in five directions and returns into the crank chamber 12 through there. Therefore, it is possible to prevent the amount of oil stored in the crank chamber 12 from decreasing as much as possible.

Note that the present invention is not limited to the embodiments described above, and can be modified in various ways. For example, the oil separator 52 is connected to the discharge port 3.
3, and even if it is not provided, a certain amount of oil contained in the refrigerant falls into the oil reservoir 51 formed at the lower part of the discharge port 33 and is stored therein.

[Effects of the invention] As explained above, according to the invention, the amount of oil leaking from the crank chamber into the cooling cycle is reduced, an appropriate amount of oil is always stored in the crank chamber, and a variable capacity swash plate type compressor is developed. It is possible to improve the durability of the movable parts or sliding parts in the.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing the piston discharge process in a variable capacity swash plate compressor according to an embodiment of the present invention, FIG. 2 is a schematic sectional view showing the piston suction process in the compressor according to the same embodiment, and FIG. The figure is a schematic cross-sectional view when the crank chamber pressure changes in the compressor according to the same example,
4 is a cross-sectional view along the line shown in FIG. 1, FIG. 5 is a cross-sectional view along the line shown in FIG. 4, and FIG.
The figure is a schematic diagram of a typical automotive cooling cycle. 11... Drive shaft, 12... Crank chamber, 13...
... Drive swash plate, 16 ... Wobble plate, 23 ... Piston, 29 ... Suction port, 33 ... Discharge port, 36 ... First control valve, 39 ... Second control valve,
50... Pipe line, 51... Oil reservoir, 52... Oil separator, 53... Opening.

Claims (1)

[Scope of utility model registration request] In the crank chamber 12, a non-rotating wobble plate 16 is slidably connected to a drive swash plate 13 which is connected to the drive shaft 11 at a variable angle of inclination, and a plurality of rods 22 are connected to the wobble plate 16. The pistons 23 connected to each other are housed in the cylinder 25 in a reciprocating manner so as to form a compression chamber 26 communicating with the suction port 29 and the discharge port 33 on the front surface of the piston 23. By changing the pressure of the wobble plate 16
and a variable capacity swash plate type compressor that changes the reciprocating stroke of the piston 23 by changing the inclination angle of the drive swash plate 13 with respect to the drive shaft 11.
The suction port 29 and the discharge port 33 are communicated with each other through the control valves 36 and 39 to connect the crank chamber 1.
2, an oil reservoir 51 is formed at the bottom of the discharge port 33, and the pressure inside the discharge port 33 and the second
The control valve 39 is connected to the opening 5 near the bottom of the oil reservoir 51.
3. A variable capacity swash plate type compressor, characterized in that the compressor is connected by a conduit 50 having three parts.